jsreport ships the official node.js client which you can use to remotely communicate with the jsreport server API.
Additionally, jsreport is implemented in the node.js and can be easily customized through javascript or run as a part of another node application. See the article jsreport in node.js for the details how to integrate or adapt jsreport.
If the jsreport official package isn't the best fit for you. You can use the minimal jsreport core and build your app from the exact extensions you are interested in. See jsreport-core for the details.